盐碱不同胁迫下紫花苜蓿关键基因的分离及其功能和分子表达调控机制的研究

Salinizationis a critical environmental and resources factor that limit agricultural production worldwide. Alfalfa (Medicago sativa L.) is an important worldwide leguminous forage crop. It is a perennial forage legume of great agronomic importance worldwide. To date, Extensive physiology and biological studies have elucidated the regulatory mechanisms of stress-responsive expression,and many New varieties should prove useful for improving plant salt and alkali tolerance. However, the effect is not very ideal, too much attention to salt stress and no sufficient knowledge of the difference between the salt stress and alkali stress are the main reasons. Furthermore, few research about difference and correlation of molecular mechanism between salt and alkali tolerance exacerbated this trend. Auxin response genes ARF and IAA are the key genes in auxin signaling pathway, but their participation in abiotic stress is less reported.In the study, ARF and IAA were obtained by high throughput transcriptome sequencing. Construction of over expression and RNAi vector transformation of alfalfa to obtain transgenic plants; The effects of ARF and IAA genes on plant development and tolerance under salt stress were analyzed; Analysis of the regulatory ARF and IAA gene expression of miRNA to improve its post transcriptional regulatory mechanism;Screening of yeast cDNA library by yeast two hybrid screening to obtain the key proteins interacting with ARF and IAA protein, and then to improve the post-translational regulation mechanism. In conclusion, through the study of auxin response gene function and expression regulation mechanism of salt stress for cross study of auxin pathway and ABA pathway of abiotic stress interaction mechanism provides a new way of thinking, to the use of genetic engineering techniques to improve the alfalfa germplasm resources, has important theoretical and practical value.

紫花苜蓿是我国规模化改良盐碱地和发展现代畜牧业的重要作物。人们通过转耐盐基因手段提高紫花苜蓿对盐碱适应效果不是很理想。过多重视盐胁迫忽略碱胁迫进而缺乏对盐碱不同胁迫下分子适应机制研究是导致这一结果的重要原因。生长素响应基因ARF和IAA 是生长素信号通路上的关键基因，但其参与非生物胁迫的报道较少。项目组利用高通量转录组测序分离到紫花苜蓿抗盐碱关键基因ARF和IAA（既抗盐又抗碱）。构建超表达和RNAi载体转化紫花苜蓿获得转基因植株；分析ARF和IAA 基因在盐碱胁迫下对植株发育和耐受能力的影响；分析调控ARF和IAA 基因表达的miRNA完善其转录后调控机制；建立并筛选酵母双杂文库获得与ARF和IAA蛋白互作的关键蛋白完善其翻译后调控机制。通过对盐碱胁迫下生长素响应基因功能及其表达调控机制研究为研究生长素途径与ABA等非生物胁迫途径的交叉互作机制提供了新的思路，具有重要的理论和实践价值。

紫花苜蓿是我国规模化改良盐碱地和发展现代畜牧业的重要作物。人们通过转耐盐基.因手段提高紫花苜蓿对盐碱适应效果不是很理想。过多重视盐胁迫忽略碱胁迫进而缺乏对.盐碱不同胁迫下分子适应机制研究是导致这一结果的重要原因。生长素响应基因ARF和IAA.是生长素信号通路上的关键基因，但其参与非生物胁迫的报道较少。项目组利用高通量.转录组测序分离到紫花苜蓿抗盐碱关键基因ARF和IAA（既抗盐又抗碱）。构建超表达和RN.Ai载体转化紫花苜蓿获得转基因植株；分析ARF和IAA 基因在盐碱胁迫下对植株发育和耐.受能力的影响；分析调控ARF和IAA 基因表达的miRNA完善其转录后调控机制；建立并筛选.酵母双杂文库获得与ARF和IAA蛋白互作的关键蛋白完善其翻译后调控机制。通过对盐碱胁.迫下生长素响应基因功能及其表达调控机制研究为研究生长素途径与ABA等非生物胁迫途.径的交叉互作机制提供了新的思路，具有重要的理论和实践价值。